iproute: fix parsing and matching of of "short" IP addrs like 10/8

function                                             old     new   delta
print_route                                         1613    1813    +200
get_addr_1                                           209     258     +49
get_prefix                                           393     356     -37
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 249/-37)           Total: 212 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

4 files changed, 74 insertions, 38 deletions

diff --git a/networking/libiproute/iproute.c b/networking/libiproute/iproute.c
index 393a376ac..f8a67d9ee 100644
--- a/networking/libiproute/iproute.c
+++ b/networking/libiproute/iproute.c
@@ -82,7 +82,7 @@ static int FAST_FUNC print_route(const struct sockaddr_nl *who UNUSED_PARAM,
 {
         struct rtmsg *r = NLMSG_DATA(n);
         int len = n->nlmsg_len;
-        struct rtattr * tb[RTA_MAX+1];
+        struct rtattr *tb[RTA_MAX+1];
         char abuf[256];
         inet_prefix dst;
         inet_prefix src;
@@ -159,8 +159,21 @@ static int FAST_FUNC print_route(const struct sockaddr_nl *who UNUSED_PARAM,
         }
 
         memset(tb, 0, sizeof(tb));
+        memset(&src, 0, sizeof(src));
+        memset(&dst, 0, sizeof(dst));
         parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
 
+        if (tb[RTA_SRC]) {
+                src.bitlen = r->rtm_src_len;
+                src.bytelen = (r->rtm_family == AF_INET6 ? 16 : 4);
+                memcpy(src.data, RTA_DATA(tb[RTA_SRC]), src.bytelen);
+        }
+        if (tb[RTA_DST]) {
+                dst.bitlen = r->rtm_dst_len;
+                dst.bytelen = (r->rtm_family == AF_INET6 ? 16 : 4);
+                memcpy(dst.data, RTA_DATA(tb[RTA_DST]), dst.bytelen);
+        }
+
         if (G_filter.rdst.family
          && inet_addr_match(&dst, &G_filter.rdst, G_filter.rdst.bitlen)
         ) {
@@ -426,7 +439,8 @@ IF_FEATURE_IP_RULE(ARG_table,)
                                 NEXT_ARG();
                         }
                         if ((**argv < '0' || **argv > '9')
-                         && rtnl_rtntype_a2n(&type, *argv) == 0) {
+                         && rtnl_rtntype_a2n(&type, *argv) == 0
+                        ) {
                                 NEXT_ARG();
                                 req.r.rtm_type = type;
                                 ok |= type_ok;
diff --git a/networking/libiproute/libnetlink.c b/networking/libiproute/libnetlink.c
index 547013ff6..c7533a4a7 100644
--- a/networking/libiproute/libnetlink.c
+++ b/networking/libiproute/libnetlink.c
@@ -393,7 +393,7 @@ void FAST_FUNC parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, in
                 if (rta->rta_type <= max) {
                         tb[rta->rta_type] = rta;
                 }
-                rta = RTA_NEXT(rta,len);
+                rta = RTA_NEXT(rta, len);
         }
         if (len) {
                 bb_error_msg("deficit %d, rta_len=%d!", len, rta->rta_len);
diff --git a/networking/libiproute/utils.c b/networking/libiproute/utils.c
index d32db8de5..d0fe30605 100644
--- a/networking/libiproute/utils.c
+++ b/networking/libiproute/utils.c
@@ -83,20 +83,43 @@ int get_addr_1(inet_prefix *addr, char *name, int family)
                 return 0;
         }
 
-        addr->family = AF_INET;
         if (family != AF_UNSPEC && family != AF_INET)
                 return -1;
+
+        /* Try to parse it as IPv4 */
+        addr->family = AF_INET;
+#if 0 /* Doesn't handle e.g. "10.10", for example, "ip r l root 10.10/16" */
         if (inet_pton(AF_INET, name, addr->data) <= 0)
                 return -1;
+#else
+        {
+                unsigned i = 0;
+                unsigned n = 0;
+                const char *cp = name - 1;
+                while (*++cp) {
+                        if ((unsigned char)(*cp - '0') <= 9) {
+                                n = 10 * n + (unsigned char)(*cp - '0');
+                                if (n >= 256)
+                                        return -1;
+                                ((uint8_t*)addr->data)[i] = n;
+                                continue;
+                        }
+                        if (*cp == '.' && ++i <= 3) {
+                                n = 0;
+                                continue;
+                        }
+                        return -1;
+                }
+        }
+#endif
         addr->bytelen = 4;
         addr->bitlen = -1;
+
         return 0;
 }
 
-static int get_prefix_1(inet_prefix *dst, char *arg, int family)
+static void get_prefix_1(inet_prefix *dst, char *arg, int family)
 {
-        int err;
-        unsigned plen;
         char *slash;
 
         memset(dst, 0, sizeof(*dst));
@@ -108,48 +131,50 @@ static int get_prefix_1(inet_prefix *dst, char *arg, int family)
                 dst->family = family;
                 /*dst->bytelen = 0; - done by memset */
                 /*dst->bitlen = 0;*/
-                return 0;
+                return;
         }
 
         slash = strchr(arg, '/');
         if (slash)
                 *slash = '\0';
-        err = get_addr_1(dst, arg, family);
-        if (err == 0) {
+
+        if (get_addr_1(dst, arg, family) == 0) {
                 dst->bitlen = (dst->family == AF_INET6) ? 128 : 32;
                 if (slash) {
+                        unsigned plen;
                         inet_prefix netmask_pfx;
 
                         netmask_pfx.family = AF_UNSPEC;
                         plen = bb_strtou(slash + 1, NULL, 0);
                         if ((errno || plen > dst->bitlen)
-                         && (get_addr_1(&netmask_pfx, slash + 1, family)))
-                                err = -1;
-                        else if (netmask_pfx.family == AF_INET) {
+                         && get_addr_1(&netmask_pfx, slash + 1, family) != 0
+                        ) {
+                                goto bad;
+                        }
+                        if (netmask_pfx.family == AF_INET) {
                                 /* fill in prefix length of dotted quad */
                                 uint32_t mask = ntohl(netmask_pfx.data[0]);
                                 uint32_t host = ~mask;
 
                                 /* a valid netmask must be 2^n - 1 */
-                                if (!(host & (host + 1))) {
-                                        for (plen = 0; mask; mask <<= 1)
-                                                ++plen;
-                                        if (plen <= dst->bitlen) {
-                                                dst->bitlen = plen;
-                                                /* dst->flags |= PREFIXLEN_SPECIFIED; */
-                                        } else
-                                                err = -1;
-                                } else
-                                        err = -1;
-                        } else {
-                                /* plain prefix */
-                                dst->bitlen = plen;
+                                if (host & (host + 1))
+                                        goto bad;
+
+                                for (plen = 0; mask; mask <<= 1)
+                                        ++plen;
+                                if (plen > dst->bitlen)
+                                        goto bad;
+                                /* dst->flags |= PREFIXLEN_SPECIFIED; */
                         }
+                        dst->bitlen = plen;
                 }
         }
+
         if (slash)
                 *slash = '/';
-        return err;
+        return;
+ bad:
+        bb_error_msg_and_die("an %s %s is expected rather than \"%s\"", "inet", "prefix", arg);
 }
 
 int get_addr(inet_prefix *dst, char *arg, int family)
@@ -163,15 +188,12 @@ int get_addr(inet_prefix *dst, char *arg, int family)
         return 0;
 }
 
-int get_prefix(inet_prefix *dst, char *arg, int family)
+void get_prefix(inet_prefix *dst, char *arg, int family)
 {
         if (family == AF_PACKET) {
                 bb_error_msg_and_die("\"%s\" may be inet %s, but it is not allowed in this context", arg, "prefix");
         }
-        if (get_prefix_1(dst, arg, family)) {
-                bb_error_msg_and_die("an %s %s is expected rather than \"%s\"", "inet", "prefix", arg);
-        }
-        return 0;
+        get_prefix_1(dst, arg, family);
 }
 
 uint32_t get_addr32(char *name)
@@ -204,10 +226,10 @@ void duparg2(const char *key, const char *arg)
         bb_error_msg_and_die("either \"%s\" is duplicate, or \"%s\" is garbage", key, arg);
 }
 
-int inet_addr_match(inet_prefix *a, inet_prefix *b, int bits)
+int inet_addr_match(const inet_prefix *a, const inet_prefix *b, int bits)
 {
-        uint32_t *a1 = a->data;
-        uint32_t *a2 = b->data;
+        const uint32_t *a1 = a->data;
+        const uint32_t *a2 = b->data;
         int words = bits >> 5;
 
         bits &= 0x1f;
diff --git a/networking/libiproute/utils.h b/networking/libiproute/utils.h
index 93c9d25d6..5fb4a862c 100644
--- a/networking/libiproute/utils.h
+++ b/networking/libiproute/utils.h
@@ -58,9 +58,9 @@ struct ipx_addr {
 
 extern uint32_t get_addr32(char *name);
 extern int get_addr_1(inet_prefix *dst, char *arg, int family);
-/*extern int get_prefix_1(inet_prefix *dst, char *arg, int family);*/
+/*extern void get_prefix_1(inet_prefix *dst, char *arg, int family);*/
 extern int get_addr(inet_prefix *dst, char *arg, int family);
-extern int get_prefix(inet_prefix *dst, char *arg, int family);
+extern void get_prefix(inet_prefix *dst, char *arg, int family);
 
 extern unsigned get_unsigned(char *arg, const char *errmsg);
 extern uint32_t get_u32(char *arg, const char *errmsg);
@@ -77,7 +77,7 @@ extern const char *format_host(int af, int len, void *addr, char *buf, int bufle
 void invarg(const char *, const char *) NORETURN;
 void duparg(const char *, const char *) NORETURN;
 void duparg2(const char *, const char *) NORETURN;
-int inet_addr_match(inet_prefix *a, inet_prefix *b, int bits);
+int inet_addr_match(const inet_prefix *a, const inet_prefix *b, int bits);
 
 const char *dnet_ntop(int af, const void *addr, char *str, size_t len);
 int dnet_pton(int af, const char *src, void *addr);